The favorite philosophy of scientists who study the universe is called the “principle of mediocrity,” and at its core shows that the Earth, the sun, and our galaxy are nothing special compared to Earth. other parts of the universe.
Now, a new survey at the University of Colorado in Boulder adds more evidence to the banal situation: On average, galaxies are at rest relative to the early universe.
Jeremy DarlingA professor of astrophysics at the same university, recently published the cosmological discovery in The Astrophysical Journal Letters.
“What this survey tells us is that we have interesting movement, but that interesting movement is consistent with what we know about the universe — Nothing special happens here,” Darling said. “As galaxies or observers, we’re not special. “
About 35 years ago, scientists discovered microwave cosmic backgroundthe electromagnetic radiation left over from the formation of the universe at the Big Bang.
The cosmic microwave background appears warmer in the direction of our motion and cooler in the direction away from our motion.
From this glow in the early universe, scientists can infer that the sun — and Earth in orbit — andis moving in a certain directionat a certain speed.
The researchers found that the speed we inferred was a fraction of one percent of the speed of light— small but not zero.
Scientists can independently test this inference by counting the number of galaxies visible from Earth or adding up their brightness.most of them can Thanks to Einstein’s Special Theory of Relativity From 1905, it explains how speed affects time and space.
In this app, a person on earth looking at the universe from one direction (the direction the sun and earth move) should see brighter galaxies, bluer and more concentrated.
Likewise, when looking in the opposite direction, one should see fainter, redder, and more widely spaced galaxies.
But when researchers have been trying to calculate galaxies in recent years — a process that is difficult to do precisely — they came up with numbers that suggest the sun is moving much faster than previously thought, which is inconsistent with standard cosmology.
“It’s hard to count galaxies in the sky —You’re usually stuck in one or fewer hemispheres,” Darling said. “And, our own galaxy doesn’t bother to count. Its dust makes us contain fewer galaxies and makes them appear dimmer. “
Darling is both curious and confused Armed with this cosmological puzzle, he decided to investigate it himself.
He also knows that two recently released surveys could help improve the accuracy of galaxy counts and shed light on the mystery of speed: VLASS (Very Large Array Sky Survey) and RACS (Rapid Australian Square Kilometer Array Pathfinder Continuous Surveys) in New Mexico, USA Australia
Taken together, these surveys allow Darling to study the entire sky by combining views from the northern and southern hemispheres. The new survey also used radio waves, This makes it easier to “see” through dust the Milky Way, thereby improving the view of the universe.
When Darling analyzed the survey, he discovered the number of galaxies and their brightness full speed Researchers have previously inferred this from the cosmic microwave background.
“We found a bright direction and a dim direction — we found a direction with more galaxies and a direction with fewer galaxies,” he said.
“The biggest difference is that it aligns with the early universe from the cosmic microwave background and with the correct velocity. Our cosmology is healthy. “
Given Darling’s discovery different from past resultsyour work may prompt some follow-up research to confirm or challenge your results.
But in addition to advancing the field of cosmology, these results are a great real-world example of Einstein’s special theory of relativity — and show how Researchers are still putting theory into practicemore than 100 years after famous physicists first proposed it.
“I like the idea that this fundamental principle that Einstein told us a long time ago is something you can see,” Darling said.
“This is a very esoteric thing and looks super weird, but if we go out and count galaxies, we can see this spin effect. It’s not as esoteric or weird as you might think. “